1. Field of the Invention
The present invention relates to a liquid electrophotographic printer, and more particularly, to an ink leakage prevention system of a development tray for a liquid electrophotographic printer which prevents leakage of the ink contained in the development tray installed at a development unit when the development tray is installed in or separated from a main body of the printer for replacement or repair.
2. Description of the Related Art
Generally, a liquid electrophotographic printer, such as a laser printer or a copier, uses developer to first form an electrostatic latent image on a photoreceptor medium so and then produces a desired image on paper, or the like. The liquid electrophotographic printer, as shown in FIG. 1, includes a development roller 12, a cleaning roller 14, a squeegee roller 16, a blade 18, a manifold 20, a development unit 26, having development tank 22, a development tray 24, and a circulation tank 28, disposed under development unit 26.
The circulation tank 28 is provided with condensed ink and a liquid carrier from an ink tank (not shown) or a carrier tank (not shown) through a developer supply inlet 30. The circulation tank 28 mixes the ink and carrier to form developer which comprises a mixture of condensed ink, made of toner of a predetermined color, and a liquid carrier functioning as a solvent. The developer in circulation tank 28 is supplied to the development unit 26 by means of a pump 32 and a valve 34. The manifold 20, installed in the development unit 26, injects developer into a development gap G formed between a photoreceptor medium 36 and the development roller 12. The injected developer adheres to the photoreceptor medium 36 as a result of a difference in surface energy between the photoreceptor medium 36 and the development roller 12. After development is performed by development roller 12, any remaining developer on development roller 12 is cleaned by cleaning roller 14 and stored in the development tank 22. Any developer stored in the development tank 22 or squeezed by the squeegee roller 16 and wiped by the blade 18 is collected in the lower portion of the development tray 24. The collected developer is thereafter returned to the circulation tank 28 via a path 38.
When components in the development unit 26, for example, development roller 12, cleaning roller 14, or squeegee roller 16 are broken, or the injection angle or height of the manifold 20 is incorrect, the development unit 26 must be disassembled from a main body of the printer for repair and replacement.
In a printer having the above structure, disassembling the development unit 26 from the main body of the printer is difficult. Further, any developer remaining around outlet 24a of the development tray 24 may fall on components of the main body of the printer, possibly damaging parts of the main body of the printer. If the developer contacts expensive parts, such as an optical system of a laser unit (not shown), damage becomes serious.
Accordingly, several potentially damaging situations may arise in a typical printer structure as describe above wherein the development unit and the circulation tank are vertically arranged in order to reduce the size of the main body of the printer. Many methods have been suggested for solving the above problem, such as placing the development unit and the circulation tank at the front side and rear side of the main body of the printer, respectively, and/or providing an inclined surface at the lower portion of the development tray and installing a quick valve at the lower portion of the inclined surface. The above suggestions are impractical because they complicate the printer structure and are cost prohibitive since they require additional valve opening/shutting devices to open/shut the quick valve.